Wierd noise and transmission question

jimpierce7 · Post by **jimpierce7** » 14 Sep 2016, 21:42

2004 XC70 Cross Country with 156,000 on it.

First of two questions. This noise isn't always happening. I can't really hear it in the car and seems to happen after the engine has warmed up.

Second, the transmission seems to be a bit weird from time to time. Occasionally acting like it has a hard shift kit in it like my dad used to use on the trucks he had for towing travel trailers. Especially when down shifting into first. A couple times now it felt like it went into neutral, or stopped between shifts, when at a slow speed.
One thing I didn't see on the Carfax report was transmission fluid changes. I have noticed the lack of a dip stick.

I have never dealt with a closed system before. I found a video on changing the fluid and it doesn't look too awful bad. I'm thinking that as some automatic transmissions slip and act up when low on fluid.

Any input would be appreciated. I really hope to keep this XC70 for a while so I want to stay on top of things. It goes through about a quart of oil every couple thousand miles. Is running a straight 30 weight advisable on these or just stick with the recommended oil?

Ok, that's more than two questions isn't it? Thank you very much for any and all help.

jimpierce7 · Post by **jimpierce7** » 11 Oct 2016, 16:59

As for the noise issue, it has been suggested that it is the brake booster running on, instead of for short times as it should. The problem being the power brake booster switch.
This sound like sound advice?
What to check before I spend $100.

Post by **JRL** » 11 Oct 2016, 20:16

Unplug the vacuum booster pump
If the noise stops, there's your answer!

Post by **abscate** » 12 Oct 2016, 04:34

A quart every few thousand isn't reason to start messing with oils. Stick with the recommended but switch to synthetic next oil change, change every 7500 miles.

On the transmission, start a series of drain and fills by dumping the pan, measuring what comes out, and replacing in kind. It will be between 3-4 liters. Repeat in a month, then repeat in another month.

You can do all these by yourself in the street . .dont let the tailess monkeys at jiffylube ruin your car

Post by **JRL** » 12 Oct 2016, 07:14

Let's figure out what his problem is first.
As said unplug the pump first, if the noise stops, that's the noise!

jimpierce7 · Post by **jimpierce7** » 12 Oct 2016, 09:29

In the quiet of the morning, I believe I hear the booster pump doing it's job as it is supposed to. Half a second to a second bursts I hear the sound.
Oddly enough I haven't heard the sound as in the video in several days.
Disconnecting the booster pump a matter of disconnecting the wires from the switch?

jimpierce7 · Post by **jimpierce7** » 12 Oct 2016, 09:31

abscate wrote:A quart every few thousand isn't reason to start messing with oils. Stick with the recommended but switch to synthetic next oil change, change every 7500 miles.

On the transmission, start a series of drain and fills by dumping the pan, measuring what comes out, and replacing in kind. It will be between 3-4 liters. Repeat in a month, then repeat in another month.

You can do all these by yourself in the street . .dont let the tailess monkeys at jiffylube ruin your car

I am probably going to have to get over/change my old thinking here. This isn't a '72 Chevy Nova.

Post by **abscate** » 12 Oct 2016, 10:10

Your XC has a low pressure turbo in it, which really likes synthetic oil. No that you get huge use out of the turbo on the 101 Parking lot, but given the oil change costs the same (50% more cost, 50% longer oil change interval) there isnt much of a reason to not switch.

There is a lot of internet chaff on the imminent failure of civilization on changing from mineral to synthetic, just ignore it.

jimpierce7 · Post by **jimpierce7** » 12 Oct 2016, 12:11

abscate wrote:Your XC has a low pressure turbo in it, which really likes synthetic oil. No that you get huge use out of the turbo on the 101 Parking lot, but given the oil change costs the same (50% more cost, 50% longer oil change interval) there isnt much of a reason to not switch.

There is a lot of internet chaff on the imminent failure of civilization on changing from mineral to synthetic, just ignore it.

Only tale I know about synthetic oil was not to use it in high mileage engines. Been a long time since I've heard that.
I'm all for synthetic oil myself.

Post by **JRL** » 12 Oct 2016, 16:51

Use synthetic but make sure your breather has good negative pressure
and change it every 5k miles.
The 5 cyl is a prone to SLUDGE engine, treat it as such...